ACS Population Variables - Tract

This layer shows total population count by sex and age group. This is shown by tract, county, and state boundaries. This service is updated annually to contain the most currently released American Community Survey (ACS) 5-year data, and contains estimates and margins of error. There are also additional calculated attributes related to this topic, which can be mapped or used within analysis. This layer is symbolized to show the percentage of the population that are considered dependent (ages 65+ and <18). To see the full list of attributes available in this service, go to the "Data" tab, and choose "Fields" at the top right. Current Vintage: 2015-2019 ACS Table(s): B01001 Data downloaded from: Census Bureau's API for American Community Survey Date of API call: December 10, 2020 National Figures: data.census.gov The United States Census Bureau's American Community Survey (ACS): About the Survey Geography & ACS Technical Documentation News & Updates This ready-to-use layer can be used within ArcGIS Pro, ArcGIS Online, its configurable apps, dashboards, Story Maps, custom apps, and mobile apps. Data can also be exported for offline workflows. For more information about ACS layers, visit the FAQ. Please cite the Census and ACS when using this data. Data Note from the Census: Data are based on a sample and are subject to sampling variability. The degree of uncertainty for an estimate arising from sampling variability is represented through the use of a margin of error. The value shown here is the 90 percent margin of error. The margin of error can be interpreted as providing a 90 percent probability that the interval defined by the estimate minus the margin of error and the estimate plus the margin of error (the lower and upper confidence bounds) contains the true value. In addition to sampling variability, the ACS estimates are subject to nonsampling error (for a discussion of nonsampling variability, see Accuracy of the Data). The effect of nonsampling error is not represented in these tables. Data Processing Notes: This layer is updated automatically when the most current vintage of ACS data is released each year, usually in December. The layer always contains the latest available ACS 5-year estimates. It is updated annually within days of the Census Bureau's release schedule. Click here to learn more about ACS data releases. Boundaries come from the US Census TIGER geodatabases. Boundaries are updated at the same time as the data updates (annually), and the boundary vintage appropriately matches the data vintage as specified by the Census. These are Census boundaries with water and/or coastlines clipped for cartographic purposes. For census tracts, the water cutouts are derived from a subset of the 2010 AWATER (Area Water) boundaries offered by TIGER. For state and county boundaries, the water and coastlines are derived from the coastlines of the 500k TIGER Cartographic Boundary Shapefiles. The original AWATER and ALAND fields are still available as attributes within the data table (units are square meters). The States layer contains 52 records - all US states, Washington D.C., and Puerto Rico Census tracts with no population that occur in areas of water, such as oceans, are removed from this data service (Census Tracts beginning with 99). Percentages and derived counts, and associated margins of error, are calculated values (that can be identified by the "_calc_" stub in the field name), and abide by the specifications defined by the American Community Survey. Field alias names were created based on the Table Shells file available from the American Community Survey Summary File Documentation page. Negative values (e.g., -4444...) have been set to null, with the exception of -5555... which has been set to zero. These negative values exist in the raw API data to indicate the following situations: The margin of error column indicates that either no sample observations or too few sample observations were available to compute a standard error and thus the margin of error. A statistical test is not appropriate. Either no sample observations or too few sample observations were available to compute an estimate, or a ratio of medians cannot be calculated because one or both of the median estimates falls in the lowest interval or upper interval of an open-ended distribution. The median falls in the lowest interval of an open-ended distribution, or in the upper interval of an open-ended distribution. A statistical test is not appropriate. The estimate is controlled. A statistical test for sampling variability is not appropriate. The data for this geographic area cannot be displayed because the number of sample cases is too small.本图层展示了按性别与年龄组划分的总人口数，以人口普查区（tract）、县（county）及州（state）边界为统计单元进行呈现。 本服务每年更新一次，纳入最新发布的美国社区调查（American Community Survey, ACS）5年周期数据，包含估算值与误差边际。此外还提供与该主题相关的额外计算属性，可用于制图或分析工作。 本图层采用符号化渲染，以展示被视为受抚养人口的占比（年龄为65岁及以上，以及18岁以下人群）。若需查看本服务中可用属性的完整列表，请前往「数据」选项卡，并选择右上角的「字段」选项。 当前数据版本：2015-2019年ACS数据表（表编号：B01001） 数据下载自：美国人口普查局（United States Census Bureau）的ACS应用程序编程接口（API） API调用日期：2020年12月10日 全国统计数据来源：data.census.gov 美国人口普查局美国社区调查（ACS）：调查概况、地理与ACS技术文档、新闻与更新 本图层可直接用于ArcGIS Pro、ArcGIS Online、其可配置应用、仪表板、Story Maps、自定义应用及移动应用。数据亦可导出用于离线工作流程。若需了解更多关于ACS图层的信息，请访问FAQ页面。使用本数据时，请引用美国人口普查局与ACS。 美国人口普查局数据说明：本数据基于抽样调查，存在抽样变异性。由抽样变异性导致的估算值不确定程度通过误差边际体现。此处展示的为90%置信水平的误差边际，其含义为：估算值加减误差边际所构成的区间（即置信上下限）有90%的概率包含真实数值。除抽样变异性外，ACS估算值还存在非抽样误差（有关非抽样变异性的讨论，请参见《数据准确性》文档），本数据表未体现非抽样误差的影响。 数据处理说明： 本图层会在每年最新版本的ACS数据发布时自动更新，通常于12月完成。本图层始终包含最新可用的ACS 5年周期估算值，会在美国人口普查局发布新数据后的数日内完成年度更新。点击此处可了解更多ACS数据发布相关信息。 边界数据源自美国人口普查局TIGER地理数据库。边界数据与数据同步每年更新一次，边界版本与美国人口普查局指定的数据版本完全匹配。为满足制图需求，本图层已将水域及/或海岸线裁剪处理：对于人口普查区，水域裁剪范围源自TIGER提供的2010年AWATER（水域面积）边界子集；对于州与县边界，水域及海岸线源自50万比例尺TIGER制图边界形状文件的海岸线数据。数据表格中仍保留原始AWATER与ALAND字段（单位：平方米）。 州图层共包含52条记录，涵盖美国所有州、华盛顿哥伦比亚特区及波多黎各。 本数据服务已移除位于水域（如海洋）区域内无人口的普查区（即以99开头的普查区编码）。 百分比与衍生计数及其关联的误差边际均为计算所得值（可通过字段名中的「_calc_」前缀识别），并符合ACS的相关规范。字段别名基于ACS汇总文件文档页面提供的表壳（Table Shells）文件生成。 除-5555...已被设置为0外，其余负值（例如-4444...）均已被设置为空值。这些原始API数据中的负值用于指示以下情况： 1. 误差边际列表明无可用抽样观测值或抽样观测值过少，无法计算标准误差及误差边际，不适宜进行统计检验； 2. 无可用抽样观测值或抽样观测值过少，无法计算估算值；或由于一个或两个中位数估算值落在开放式分布的最低区间或最高区间，无法计算中位数比率； 3. 中位数落在开放式分布的最低区间或最高区间； 4. 不适宜进行统计检验； 5. 估算值已受控，不适宜进行抽样变异性统计检验； 6. 由于抽样案例数量过少，无法展示该地理区域的数据。